Did unibody Macbook Pros have a backup battery (CMOS / PRAM)?

My mid-2009 13" unibody MacBook Pro died years ago. It's probably not worth fixing. I'm just curious if a dead CMOS/PRAM battery could have caused its demise? *iFixIt* doesn't list any non-primary batteries in its online store or replacement guides for any unibody Macbook Pros. Did these models lack one altogether or was it just soldered to the logic board (In which case it'd be kind of like [planned obsolescence](https://en.wikipedia.org/wiki/Planned_obsolescence)) ?